A CRITICAL PROBLEM IMPACTING U.S. RAINBOW TROUT CULTURE IS REDUCTION OF WASTE DISCHARGE TO RECEIVING WATERS. INCREASING SCRUTINY IS BEING PLACED ON FARMERS TO MANAGE WASTE. THE OBJECTIVES OF THE PROPOSED RESEARCH IS TO DEVELOP DIETARY FORMUALTIONS AND FEED PROCESSING METHODS TO REDUCE THE WASTE LOADS AND IMPROVE FECAL WASTE REMOVAL. PREVIOUSLY, WE FOCUSED ON SUSTAINABLE AQUACULTURE EFFORTS BY EVALUATING THE EFFECTS OF DIETARY REPLACEMENT (FISH-BASED TO PLANT-BASED PROTEIN SOURCES) ON RAINBOW TROUT. ALTHOUGH TROUT PERFORMED WELL ON THESE DIETS, A NEGATIVE EFFECT OF PLANT-PROTEIN (PP) BASED FEEDS ON WASTE MANAGEMENT WAS OBSERVED. INSTEAD OF PRODUCING FECAL PELLETS, RAINBOW TROUT FED A PP-BASED DIET EXHIBITED A CONDITION LIKE DIARRHEA WITH REDUCED FECAL CAST DURABILITY AND INCREASED FECAL FINES. FURTHER RESEARCH SHOWED THAT PP-BASED FEEDS INCREASED DISSOLVED WASTE (PHOSPHORUS, TSS, AMMONIA) CONTRIBUTION TO EFFLUENT AS WELL. HERE, WE PLAN TO PERFORM A SERIES OF FEEDING TRIALS USING PP-BASED FEEDS TO REDUCE SOLID WASTE PRODUCTION, IMPROVE FECAL DURABILITY, REDUCE FINES PRODUCTION, AND LOWER DISSOLVED WASTE OUTPUT. FROM THESE TRIALS, WE WILL DEVELOP IMPROVED PP-BASED FEED FORMULATIONS FOR ON-FARM TESTING UNDER COMMERCIAL CULTURE CONDITIONS. IMPROVEMENT OF FEED FORMULATION AND FEEDING STRATEGIES IS A COST-EFFECTIVE MEANS TO REDUCE WASTE OUTPUT AND IMPROVE WATER QUALITY. THIS PROJECT WILL DIRECTLY ADDRESS 'DESIGN OF ENVIRONMENTALLY AND ECONOMICALLY SUSTAINABLE COMMERCIAL AQUACULTURE PRODUCTION SYSTEMS' UNDER THE NIFA PROGRAM AREA PRIORITIES AND WILL BE INSTRUMENTAL IN FURTHER EXPANSION OF COMMERCIAL TROUT CULTURE IN A SUSTAINABLE MANNER TO MEET THE DEMANDS OF U.S. CONSUMERS.